Uses of Rasch modeling in counseling psychology research.

Abstract

Inferences made from summary indices of psychometric scales must be reliable and valid to advance scientific knowledge in counseling psychology. This article illustrates traditional and innovative uses of the Rasch model in the development and validation of small- and large-scale psychological instruments. Discussion of traditional uses of the Rasch model included reliability and validity of scale scores, whereas discussion of innovative uses included (a) determining the optimal number of response categories for Likert-type items and (b) obtaining a measure of response style for each person. Both mathematical and conceptual explanations are provided, and counseling psychology data are used to illustrate examples.

Cyberbullying: The hidden side of college students

“…Table 3 shows the Cronbach's a, the Person Separation Reliability and the Item Separation Reliability for all the scales. These scores indicate good internal consistency/reliability independently of removing participants and items with infit/ outfit values higher than 1.5, and z statistic values higher than 2.00 (Fox & Jones, 1998). The values for Person Separation Reliability in each scale, along with the difficulty indicators, reveal that these students may have had difficulty in responding to all of the items and underrated their involvement in situations of cyberbullying, thus confirming our first hypothesis.…”

A Psychometric Revision of the Asian Values Scale Using the Rasch Model

“…The Rasch analogue to Cronbach's alpha is called "person separation reliability" (Wright & Masters, 1982), which refers to the ability to differentiate persons on the measured variable and the replicability of person placement across other items measuring the same construct. The index ranges from 0 to 1, with values equal to or greater than .80 being regarded as acceptable (Fox & Jones, 1998). The person separation reliability is .86 for the PCM and .86 for the RSM, both of which are acceptable.…”

“…In addition to these analyses, the 25-item scale showed a person separation reliability of .80. As we mentioned earlier, this index ranges from 0 to 1, with values equal to or greater than .80 regarded as acceptable (Fox & Jones, 1998).…”

Development of a support needs assessment scale for children and adolescents with intellectual disabilities. [Desarrollo de una escala de evaluación de necesidades de apoyo para niños y adolescentes con discapacidad intelectual]

“…Reliability is determined by taking the reason for the 'truescore variances' and 'observed-score variance.' Values range from 0 to 1 with acceptable values of .80 or greater (Fox & Jones, 1998). The value obtained in our data is over .95 for each dimension in the scale which is even higher than what is considered acceptable reliability.…”